Shoe sewing machine



July 31, 1951 M. MUC 25623510 SHOE SEWING MACHINE Filed March 14, 194'?2 Sheets-Sheet l INVENTOR.

/LW mm July 31, 1951 Filed March 14, 194'? M. MUC

SHOE SEWING MACHINE 2 Sheets-Sheet 2 IINVENTOR.

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Patented July 31, 1951 2,562,810 p srioE sawnie Mannini:

Miioslav Muc, Slatinice, near Glomouc, Czecho- Slovakia, assignor toBata, narodni podnik, Zlin,

- l Czechoslovakia Application March 14, 1947, Serial No. 734,754 InGermany December 1, 1942 Section 1, Public Law 690, August 8, 1946Patent expires December 1, 1962 Cl. Ime-46) i Claims. l

' This invention relates to shoe sewing machines and in particular tomachines for attaching the sole to the upper leather by means of adecorative welt or a false welt sewn around the edge of the sole.

OneI of the problemsencountered in sewing o n the welt which is usuallyfed from a large roll is to cut it off at the proper place so that whenthe sole has been sewn around the entire periphery, the two ends of thewelt willL meet exactly.

The prior methods and machinery for cutting the welt have4 not beencompletely satisfactory. One technique which has been used is to controlthe operation of the cutting device in accordance with an impulse orcontrol signal from the return of the beginning end of the welt alreadysewn on tothe sewing location. In one device of this type a specialfeeler is provided that is arranged independent of the guide member forthe welt strip and upon traveling up against the beginning of the weltreleases the cutting knife, by whose mechanically instigated movementagainst the guide member of the welt, the latter is cut olf.

This type of device has however many disadvantages. One drawback residesin the fact that the cutting knife has to be removed from its guide eachtime that it is sharpened. This is a very tedious operation andfurthermore the knife must be readjusted into the exact positionnecessary for the correct cutting stroke whenever it is sharpened.

In another known automatic welt cutter of the impulse type, the cuttingknife remains in a fixed position and is structurally combined with theguide member for the weltstrip into one piece. However, this arrangementis also unsatisfactory for the reason that continued resharpening of theknife ultimately renders the whole guide useless and it must bereplaced.

The improved method according to the present invention permitselimination of the drawbacks mentioned and alsothe construction of anewsatisfactory device for automatic cutting-off of the welt strip and isbased on the fact that by the impulse given by theV traveling up on thebeginning of the welt already sewed on, an automatic stroke of the guidemember of the welt against an immovably mounted knife is released andthereby the welt is cut off. This process makes possible an advantageouscombination of a number of actions in a single member, specilically theguide member of the Welt strip itself, that acts at the same time asfeeler for feeling the welt origin and for releasing the stroke deviceagainst the fixed knife and preferably likewise forms a part of the feeddevice of the machine. The device serving for carrying on the methodaccording to the invention therefore offers appreciable advantages overall constructions of welt cutting devices disclosed heretofore. Afurther advantage yielded by the invention is good visibility of thework place and convenient `exchangeability of the easily accessible xedknife, that can be easily adjusted.

Further advantages and features of the invention will be apparent fromthe following description of one constructional example in connectionwith the appended drawings.

. Fig. 1, a view in perspective, illustrates the whole apparatus of acutting device for a duplex machine operating according to theinvention.

Fig. 2, likewise a perspective View, shows the appertaining controlmechanism on a larger scale.

Fig. 3 is a view in elevation of the working place during normal sewing.

And Fig. 4 is the same elevational view in the condition iust before thecutting olf of the welt.

The constituents of the sewing device carrying barbed needle I and theawl 2 already known per se are omitted from the drawings for the sake ofclarity; these drive members can be constructed and arranged in anysuitable way.

The needle I and the awl 2 describe reciprocating motions in a circularpath through a slotv 3- in the customary support 4 for the piece of work4a. In the direct neighborhood of the work support 4 is located thecutting knife 5 and aA foot e through the opening 'I of which is led thewelt strip 8 taken from a receptacle that is not shown. The knife 5 iscurved and adjustable, for instance anchored by means of a screw 9 rin aholder Ill that is carried by a bracket II. This' bracket Il is mountedto slide with all its con-V stituents on a pin l2 of the Xed machine armI 3. The guide foot 6 of the welt 8 is likewise secured in a removableand adjustable manner inV a guide I4 of the lower arm of a two-armedlever I5, specifically by means of a screw I 6. The twoarmed lever l5 ismounted so as to turn-on a pin Il of the bracket I I already mentioned,which in addition carries a pivot I8 of the two-armed lever I9 likewisemountedto swing. Tothe upper arm of this lever IS is secured aprojection 2li carrying the channel cutter 2l for cutting the solegroove receiving the seam, this projection 2D likewise carrying atoothed feeder foot 22 (cf. Fig. 3) for the stitch-like advance of thepiece of work. The bracket II is given the ordinary reciprocatingmovement along the pin l2 for the purpose of stitch-like advance of thepiece.

of work, the feeder foot 22 from above and the foot 6 from belowalternately clamping and freeing the piece of work. The guide foot 6 inthis connection thus performs the function usually performed by theworksupport in alternately clamping and releasing the piece of work foradvancing the same.

The upper arm of the lever i carries a ball pivot 23 of the draw-bar 24,the opposite end of which is likewise hung by a ball pivot 25. This ballpivot 25 changes over into a cylindrical pin 26 (cf. Fig. 2) on whichengages, on the one hand, the fork 21 of a draw-bar 28 and on the otherhand a rail 29 that for instance has a U-prole and is guided so as toslide in the recess 3U of a bracket 3| mounted in a fixed fashion in themachine frame. In the lower part of the recess 30 of the bracket 3| isprovided an inclined slot 32, in which roller 33 is laid and pressed bya spring 34 against the narrow side of the slot, this roller thusclamping the rail 29 in the recess 36; the release of the lockconstituted by members 32, 33, 34 is accomplished by pressure on theroller 33 by means of a bolt 35 against the influence of the spring 34.This bolt 35 is governed by the projection 36 of a two-armed lever 31,that is mounted so as to turn on a pin 38 of the bracket 3| and by meansof a roller 39 is actuated by a cam 4U provided on the main shaft 4| ofthe machine. The parts 42 and 43 of the cam track 40 correspond to thelocked position of the roller 33 while the projection 44 causes therelease of the lock members 32, 33 and 34.

Besides the cam 46, an additional cam 45 is provided that has a deepnotch 46 and a slight projection 41. This cam 45 acts on the roller 48of a three-armed lever 49, that can turn on a pivot 5U mounted fast inthe machine frame (Fig. 1). The roller 48 is held in engagement with thecam 45 by a spring 5| hooked to the lower arm 52 of the lever 49. To theupper arm 53 of the lever 49 is secured a pivot 54 on which the draw-bar28 with a long recess is suspended. The drawbar 28 is constantly drawnto the right by a spring 52 hooked on the one hand in the pivot pin 26and on the other hand in the pivot pin 54, the long recess 55 furnishingplay for the guide foot 6 agreeing with the thickness of the welt 8(Figs. 3 and 4). The highest position of the guide foot 6 is determinedby the striking of a bolt 13 against the end of a groove 14 in thebracket 3| Fig. 2). In order that the lock, comprising members 32, 33and 34 of the rail 29 can be held in the released position independentof the position of cam 40 or of its projection 44 (for reason to beexplained later), an angle lever 51 furnished with a pawl 66 is placedin front of the bolt 35 or the projection 36 of the lever 31, this anglelever being capable of turning on the pin 58 of a supporting plate 59secured to the bracket 3|. The upper arm of the angle lever 51 isprovided with a fork 60 in which an adjustable bolt 6| (Fig. 1) of thedraw-bar 24 engages.

In order' to be able to set the cutting device entirely out of operationfor any desired length of time, the lower arm of the three-armed lever49 is provided with a stop 62 (Fig. 1) on which the pawl 63 comes torest, this preventing the lever 49 from swinging out under the iniluenceof the spring 5|. The pawl.63 is mounted so that it can turn on a pivot64 mounted in the machine frame and is shifted by means of a linkagesystem comprising members 65, 66, 61, 68, 69 and 10 by a bowed member1|, the latter being controlled for instance by a knee of the operatorserving the machine. This entire lever system is under the influence ofa spring 12 so that as long as no force is exerted on the knee-bowmember 1| from outside, the pawl 63 is in engagement with the stop 62and the cutting device is thus out of operation.

The method of operation of the device described is as follows:

During sewing, the cam shaft 4| receives a turning motion in thedirection Si (Fig. l) whereby the needle and the awl 2 describe thenormal working movements and sew the welt strip 8 to the upper part andthe sole 4a of the shoe being made. The lateral movement of theprojection 20 carrying the feeder foot 22 necessary for this and of thefoot 6 takes place with the help of the bracket to which this movementis transmitted in the ordinary way from the cam shaft through a devicenot shown.

From the beginning of the sewing operation on a piece of work up to justbefore completion of the sewing over the entire periphery of the shoesole 4a, the cutting device of the welt strip 8 remains set out ofoperation since the pawl 63 holds the stop 62 fast, as already describedearlier. When the sewing operation has almost reached the end, theoperator presses the knee bow 1| to the right (according to Fig. 1) sothat with the aid of the lever system already described, the pawl 63 isbrought out of engagement with the stop 62 and then all the requirementsfor the cutting off of the welt at the required moment are met, i. e.upon traveling up of the foot 6 on the Welt origin already sewed on.

The cutting operation proceeds as follows:

Upon each rotation o f the cam shaft 4|, that corresponds to a stitch,the projection 44 of the cam 40 effects a release of the lock (32, 33,34) of the rail 29. This releasing action is obtained by upward movementof roller 39, which causes the projection 36 of the two-armed lever 31to be forced in the direction S3 (Fig. 2), thus caus ing the bolt 35 tobe pressed against the locking roller 33. The latter is thus pushed backagainst the influence of the spring 34 and the rail 29 is freed. If atthis moment, the foot 6 however is not pushed down at the same time, i.e. the foot assumes the position shown in Fig. 3, the projec tion 36 ofthe lever 31 goes right back to its original position after theprojection 44 of the cam 4U has turned past and the roller 33 againblocks the sliding movement of the rail 29 to the left. Thus in thiscase, even with released pawl 63, the roller 48 of the lever 49 cannotfollow the cam track 45 and the recess 46 since the lever 49 cannotswing out, because of the firmly locked rail 29. The same operation isrepeated at each stitch as long as the foot 6 slides along the surfaceof the piece of work still not covered by the welt strip 8, as accordingto Fig. 3, during the reverse movements of the feeder device.

Just before the completion of the sewing op? eration, the moment isfinally reached when the foot 6 rides up on the beginning of the welt 8'already sewed on; Fig. 4 shows this moment. Since the cam position isadjusted so that the foot 6 describes its reverse movement in rela-tionto the piece of work at a time in which the rail 29 is just liberatedunder the influence of the projection 44 of the cam 4U, then upon thedepressing of the foot 6, due to its traveling up on the beginning ofthe welt 8, the draw-bar 24 withthe rail 29 and the draw-bar 28 arepushed to the left (Fig. 1) against the pull of the spring 5|, the longrecess 55 of the draw-bar 28 sliding Qn the Pin. 54 Qi the lever 5.3 andthe pin 6l of' y 5 the .draw-.bar f2s shifting the forky 0 vinto Atheposition shown in Fig. 2 by solid lines 'In this position the pawl diirests Vagainst the projection t that has just taken up its positionreleasing the lock (-32, 38, .54) of the rail 2.9. Meanwhile u the foot5 has traveledcompletely upon the beginning of the welt, the pivot Si.and with it likewise the fors t@ remains in the position shown in Fig.2, even when the projection 114 ofthe cam de has run past the roller Silso that the latter o,

into the position shown bydotted lines in Fig.`

4. The cutting-off of the welt strip B occurs during this swinging,since it is moved down forcibly by the foot against the edge of theknife 5. The moment of cutting off is thereby adjusted exactly to thewelt beginning already sewed on. The operator can then finish sewing theremaining stitches and after lifting off the feeder foot 2c can removethe piece of work from the machine.

The foot 5, after the welt strip 8 is cut off, is lifted again by thecam 45, so that the draw bars 2d and 28 go back to their originalpositions, the pin 5i of the pull rod 24 putting back the fork 69iikewise into the original position shown by dotted lines in Fig. 2. Theprojection 36 is thus freed and can be shifted again to the left untilthe roller 3S of the lever 3l rests on the cam 4l] and the lock 32. 33,34 goes into operation as soon as the roller 39 leaves the projection 44of the cam it. The working operation is then completed and can berepeated in the same way with the next piece of work.

A main feature of the device according to the invention is to be foundin the fact that guide foot 5 does a whole series of tasks; it serves asguide member for the welt strips, as an aid to the feed device of theduplex machine and finally as a feeler for feeling the beginning of thewelt and for releasing the cutting device.

In conclusion, it will now be evident that the novel method of cutting@if the welt according to the invention is predicated upon an impulseinstigated by the return of the beginning end of the welt which resultsin a forced stroke of the ,guide member for the welt 8 against a xedknife 5. Furthermore, it will be understood that while the illustratedmachine for carrying out the novel method of cutting off vthe welt is tobe preferred, changes in the construction of the machine parts as wellas substantially different machine arrangements may be effected withoutdeparting from the spirit and scope of the invention.

1. In a sewing machine for use in the manufacture of shoes, thecombination with stitch forming mechanism acting to secure a weltprogressively around a shoe, of a welt guide for dil recting the weltinto proper position on the shoe upper in advance of the sewing point,means supporting the welt guide to allow an initial motion thereof uponcontact with the return of the beginning end of the sewn on welt, astationary knife positioned adjacent the guide, and means conditioned inresponse to the initial motion of said guide for effecting an additionalmotion 6 .thereof tobring the weltfagainst and-becutjhy vsaid knife.

2. In a sewing vmachine for use in the manufacture of shoes, thecombination with stitch forming mechanism acting to .secure a `weltprogressively around a shoe, of a welt guide fordirecting 'the welt intoproper position on the shoe upper in advance `of the sewing point,Ameans supporting said welt guide to permit an initial downward motionthereof upon contact withthe return of the beginning `end of the sewn onwel-t, a stationary knife positioned below said welt,

vand means conditioned in response to the initial motion of said guidefor effecting a further down- `ward motion thereof to bring the weltagainst and be cut by said knife. y

3. A sewing machine as defined in claim 2 and further including meanslocking said last named means in an inoperative position and a manuallyactuated device for releasingv said locking means. l

4. In a sewing machine for use in the manufacture of shoes, thecombination with stitch forming apparatus to secure a welt progressivelyaround a shoe, and a reciprocatory feed device for feeding the shoe pastthe sewing point, of a welt guide for directing the welt into properposition on the shoe upper in advance of the sewing point, said weltguide also constituting a feeder foot of the feed device, meanssupporting said welt guide to allow an initial downward motion thereofupon contact with the return of the beginning end of the sewn on portionof the welt, a stationary knife positioned below said welt, mechanismconditioned by the initial motion offrsaid guide for effecting furtherdownward motion thereof to bring the welt against and be cut by saidknife, and means controlled in timed relation with operation of saidfeed device for determining the operating moment of said mechanism.

5. In a sewing machine for use in the manufacture of shoes, thecombination with stitch forming apparatus to secure a welt progressivelyaround a shoe and a reciprocatory feed device for feeding the shoe pastthe sewing point, of a welt guide for directing the welt into properposition on the shoe upper in advance of the sewing point, said weltguide also constituting a feeder foot of the feed device, meanssupporting said welt guide to effect a downward motion thereof uponcontact with the return of the beginning point of the sewn on portion ofthe welt, a stationary knife positioned below said welt, mechanismconditioned by initial motion of said guide for effecting further motionthereof to bring the welt against and be cut by said knife, a manuallyactuated device for rendering said mechanism incapable of operation, andmeans controlled in timed relation with the operation of said feeddevice for also holding said mechanism inoperative except when said weltguide occupies its rearmost position in the feed stroke.

6. A sewing machine as defined in claim 5 wherein said welt guide issupported by a pivoted lever and said mechanism for depressing said weltguide is constituted by a spring loaded lever system connected to saidpivoted lever.

'7. In a sewing machine for use in the manufacture of shoes, thecombination with a stitch forming apparatus to secure a weltprogressively around a shoe and a reciprocatory feed device for feedingthe shoe past4 the sewing point, of a welt guide for directing the weltinto proper position on the shoe upper in advance of the sewing point,said welt guide also constituting thereof upon contact with the returnof the beginning point of the sewn on portion of the welt, a stationaryknife positioned below said Welt, a spring loaded mechanism for furtherdepressing said welt guide and Welt subsequent to the initial movementthereof to bring the welt against and be cut of! by said knife, a devicealternately locking and unlocking said mechanism as the sewingprogresses, means actuated in response to an initial depression of saidguide to secure said locking device in its unlocked position, and meanscontrolled in timed relation with the operation of said feed device for'determining the exact operating moment of said mechanism.

8. A sewing machine as dened in claim 7 and further including a manuallyoperated release for said spring loaded mechanism.

9. A sewing machine as defined in claim 1 wherein the last said means iscomprised of a cam having a depression in the cam track, said cam beingdriven by a cam shaft of the sewing machine, a cam roller mounted on onearm of 8 a. pivoted lever connected in the spring loaded mechanism, andthe latter is freed for operation when said roller rides down into thedepression in the cam track.

10. A sewing machine as defined in claim 7 wherein said mechanismincludes a rail reciprocating in a slotted portion of a stationarymember of the sewing machine, and said rail is alternately locked andunlocked relative to said slot by means including a cam and cam roller,the cam being driven by a cam shaft of the machine in such manner thatthe rail is locked and unlocked once for each stitch taken by themachine.

MUC, MILOSLAV.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,774,498 Ashworth et al. Sept.2, 1930 2,022,754 Ashworth Dec. 3, 1935 2,225,812 Wennerlund Dec. 24,1940

